1. Field of the Invention
This invention relates in general to a method for programming a microprocessor, and more particularly to a method for flash programming an embedded controller.
2. Description of Related Art
Microprocessors used as embedded controllers in high reliability systems must be able to have their programming updated in the field to correct errors and provide new features. This update must be done without adversely effecting the system being controlled and should the programming produce an error, the microprocessor must still continue to operate in a known and proper mode of operation.
Once the new program for the microprocessor has been downloaded, the microprocessor must switch to this new program gracefully, and if the new program does not operate properly, then the microprocessor must be able to recover to a known state with the prior program.
It can be seen then that there is a need for a better method of updating a microprocessor's programming. It can also be seen then that there is a need for a better transition method between a current program and an updated program. It can also be seen that there is a need for a method for returning a microprocessor to a previous program and a known state in a graceful manner when the updated program fails to operate correctly